But even a defeat can be said to advance campaign groups' narrative that Christians are being "marginalised" by militant secularism.

British Airways employee Nadia Eweida holds her crucifix as she poses for pictures after the court's ruling. Photograph: Getty Images

Today's judgement by the European Court of Human Rights in the cases of four Christians claiming discrimination[3] on the basis of their beliefs is generally a good thing. Score-keepers in the ongoing culture wars will be quick to note a three-one win by the forces of secularism. Of the four claimants, only Nadia Eweida, the British Airways check-in clerk who was told that her small silver cross violated the company's uniform policy, had her claim upheld. But her victory is more than just symbolic. It undermines the one strong argument her backers had that Christians in this country face anything that might be called oppression. The other cases usefully serve to mark out the boundaries between religious self-expression and the wider interests of society.

Taken together, the cases of Nadia Eweida and Shirley Chaplin - a nurse whose similar wish to wear a cross at work was turned down on health and safety grounds - introduce an easily-understood principle. Generally, the judges decided, employees have a right to manifest their religious convictions (their right under Article 9 of the European Convention) by wearing a symbol of their choice. Lawyers of the government had argued, much to David Cameron's embarrassment, that the principle only applies where the symbol is an explicit requirement of the faith or worn openly by a majority of the faith's adherents. The domestic courts had reached much the same conclusion. But for the European judges, it was enough that the cross is a recognised Christian symbol, and that Eweida believed that demonstrating her faith openly by wearing it was important to her. The model upheld is one of individual belief rather than corporate religious identity. The court seeks to protect the believer, not the religion as a whole. This is important.

Chaplin lost, meanwhile, because her employer had a stronger rationale for interfering with her right to manifest her belief, in this case the health and safety of patients. Eweida's relatively discreet cross posed a much more trivial challenge to her employer's corporate identity. BA itself later seemed to acknowledge this by changing the policy.

One consequence of these decisions should be to reduce any perception that the law treats Christians wishing to wear a cross less favourably than members of other religions. Pressing the belief that Christians are getting a raw deal compared to, say, hijab-wearing Muslims or turban-wearing Sikhs has been central to the agenda of campaign groups such as Christian Concern, aided and abetted by the Express and the Daily Mail. Unfortunately, the approach of the domestic courts, which have tended to restrict the Article 9 right to "manifest" religious belief to practices that are central or mandatory in a faith tradition (which wearing a cross isn't) has sometimes fostered this impression. Today's ruling may help to redress the balance.

The two Christians who wished to be exempted from offering services to gay or lesbian clients both lost their case. Lillian Ladele worked as a registrar in Islington but lost her job because she refused to register civil partnerships, while Gary McFarlane, a Relate counsellor, objected to being required to give sexual advice to same-sex couples. In both cases, the court accepted that their refusal in this way was a manifestation of the claimants' religious belief; but it found the interference justified in the light of the wider social goal of anti-discrimination. In these cases, where there was a balance to be struck between competing rights of religious manifestation and non-discrimination, the Court was content to leave matters to the discretion of the authorities concerned.

McFarlane had an especially weak case, having embarked upon a course of training in psycho-sexual therapy in the full knowledge that he would be expected to advise both gay and straight couples. In Ladele's case, however, there was a strongly worded dissent from two of the judges. Noting that when she became a registrar there was no such thing as civil partnerships and that her desire not to conduct them could have been accommodated, the judges accused Islington of having "pursued the doctrinaire line, the road of obsessive political correctness. It effectively sought to force the applicant to act against her conscience or face the extreme penalty of dismissal."

I have some sympathy with this view. There's little doubt that Ladele's objections could have been accommodated and no gay couple would have been any the wiser. Her argument always struck me as somewhat illogical, though: as an evangelical Christian she may have believed that only heterosexual marriage was valid in the eyes of God, but as a registrar she was called upon to pursue a civil function with no religious dimension whatever. All that Ladele was being asked to do was to smile sweetly, say the appointed words, and fill out some paperwork.

For campaign groups like Christian Concern and the Christian Institute, which between them represented the claimants, litigation forms an integral part of what is essentially a political strategy. On the one hand, they make full (many would say over-enthusiastic) use of the legal tools given to them by recent equality legislation as well as the growing number of cases dealt with by the European Court of Human Rights. Obviously they would prefer to win these cases. But even a defeat can be said to advance their wider narrative that Christians are being "marginalised" by militant secularism. It might even enhance their chosen self-image as an oppressed group. And the publicity that these cases inevitably attract (along with others, such as those involving guest-house owners who refuse the custom of same-sex couples) serves to rally the faithful, whether the cases themselves are won or lost.

By "Christians", of course, they mean a particular type of Christian. Not all believers share their particular obsessions (notably opposition to gay equality) or think of themselves as part of a beleaguered minority. The argument is at least as much an internal Christian one as a debate between Christians and the forces of secularism. That's the point.